Ternary composition of V sub 2 O sub 3 -MgO-SiO sub 2

Patent · Tue Mar 10 04:00:00 EST 1992

OSTI ID:5027842

Najjar, M S; Muan, A

This patent describes a method of preparing a composition involving V{sub 2}O{sub 3}, MgO and SiO{sub 2} that is crystallized from a liquid with which the composition is in equilibrium on the liquidus surface and wherein the liquid has a composition that falls within a polygon shaped shaded area ABCDE as shown in the disclosed FIGURE for a ternary composition diagram of V{sub 2}O{sub 3}, MgO and SiO{sub 2}. It comprises: heating V{sub 2}O{sub 5} powder having a particle size of less than about 50 microns in an atmosphere in which the partial pressure of oxygen is in the range of 10{sup {minus}5} to 10{sup {minus}10} atmosphere while gradually increasing the temperature over a temperature range of about 600{degrees}C. to 1300{degrees}C. and holding the final temperature for a period to ensure complete reduction of all vanadium to V{sup 3+}; heating MgO and SiO{sub 2} powders each having a particle size of less than about 50 microns for a period of about 10 to 14 hrs. at a temperature in the range of about 1000{degrees}C to 1200{degrees}C.; thoroughly grinding together an amount of V{sub 2}O{sub 3} in the range of about 30 to about 98 wt %, with an amount of MgO, in the range of greater than 0 to about 50 wt %, and an amount of SiO{sub 2} in the range of greater than 0 to about 40 wt. % to produce a mixture having a grain size of less than about 50 microns, pelletizing the mixture, at a pressure of about 5,000 psi; heating the pellets at a temperature in the range of about 1400{degrees}C to 1800{degrees}C for a period in the range of about 12 to 48 hrs. in an atmosphere in which the partial pressure of oxygen is in the range of 10{sup {minus}10} to 10{sup {minus}15} atmosphere to produce a melt; and cooling the melt and crystallizing out the composition involving V{sub 2}O{sub 3}, MgO and SiO{sub 2}, and separating the composition involving V{sub 2}O{sub 3}, MgO and SiO{sub 2} from the rest of the melt.

• Assignee: Texaco Inc., White Plains, NY (United States)
• Patent Number(s): A; US 5094992
• Application Number: PPN: US 7-590743
• OSTI ID: 5027842
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360201* -- Ceramics
Cermets
& Refractories-- Preparation & Fabrication
360202 -- Ceramics
Cermets
& Refractories-- Structure & Phase Studies
ALKALINE EARTH METAL COMPOUNDS
CHALCOGENIDES
CHEMICAL COMPOSITION
CHEMICAL PREPARATION
COMMINUTION
ELEMENTS
GRINDING
HEAT TREATMENTS
MACHINING
MAGNESIUM COMPOUNDS
MAGNESIUM OXIDES
NONMETALS
OXIDES
OXYGEN
OXYGEN COMPOUNDS
PARTICLE SIZE
POWDERS
SILICON COMPOUNDS
SILICON OXIDES
SIZE
SYNTHESIS
TEMPERATURE RANGE
TEMPERATURE RANGE 0400-1000 K
TEMPERATURE RANGE 1000-4000 K
TRANSITION ELEMENT COMPOUNDS
VANADIUM COMPOUNDS
VANADIUM OXIDES